Elio Rodrigo Castillo

I am an evolutionary biologist particularly interested in Orthopterans, with a focus on Systematics, chromosome evolution, and genomic changes. I have explored remarkable features of this insects to study lineages exhibiting chromosome mutations and evolutionary new formed sex chromosomes. My research has extended to understanding the highlighted variations in the external body coloration and the homogeneity in characters of male genitalia (commonly utilized for species determination) in specific groups. I have delved into the biology of pests and invasive species, and I have studied the phylogenetic relationship in recently diverged clades, distributed across the diverse landscapes of South America.

Currently, I am actively engaging in an unprecedented continent-wide scale project to unravel the Orthoptera cryptic diversity in Europe. Collaborating with researchers from three iDiv member institutions, our integrative approach to the study of Orthoptera biology focuses on characterizing genome size, karyotype, and sperm morphology across the European orthopteran fauna. These comprehensive datasets will enable us to (i) reconstruct the evolutionary history of genomic and reproductive diversity, (ii) correlate genomic and reproductive diversity with ecological traits of a species, and (iii) relate genomic and reproductive diversity to species richness. This will provide insight into the drivers of diversity in an important group of insects on a continent-wide scale.

Orthopterans (crickets, bush-crickets and grasshoppers) represent one of the largest groups of herbivores insects with major impacts on grassland ecosystems, but also with significant impact on tree foliage along forest edges. They are a highly diverse group of insects with unusually large genomes, high genome fluidity and reproductive diversity. Chromosome mutations are an important source of variation which could prevent the correct chromosome pairing at meiosis. Repetitive elements in large genomes and B chromosomes promote ectopic recombination and thus cause of structural variation. Structural variation can fuel adaptation or (as in the case of karyotypic variation) lead to separation of gene pools. Colour polymorphisms are known to promote speciation, however, they can also facilitate population persistence. Finally, sperm trait can promote speciation, if they coevolve with female reproductive physiology. Coevolution is likely and rapidly leads to reproductively incompatible populations.

This project aims to compile a unique dataset that will bring together phylogenetic, genome size, karyotype and sperm morphology information with existing data on distribution, habitat use, colour morph diversity and species richness within clades.

The research will address:

• The genome size mapping in a complete phylogenetic tree of orthopterans to understand when genome size increase has happened in evolution.
• A high-resolution map of karyotype evolution in orthopterans. This will allow us to understand genome fluidity and its possible consequences for diversification.
• The diversity of sperm morphology in orthopterans to elucidate the role of sexual selection in the diversification in this clade.

Durán-Fuentes, J.A., Maronna, M.M., Palacios-Gimenez, O.M., Castillo, E.R., Ryan, J.F., Daly, M. & Stampar, S.N. (2025). Repeatome diversity in sea anemone genomics (Cnidaria: Actiniaria) based on the Actiniaria-REPlib library. BMC Genomics 26: 473. doi: 10.1186/s12864-025-11591-0External link

Palacios-Gimenez, O.M., Castillo, E.R.D. & Schielzeth, H. (2025). Karyotype evolution and speciation in Orthoptera. Journal of Evolutionary Biology 38: 516-529. doi: 10.1093/jeb/voaf018External link

Guzmán, N.V., Gandini, L.M., Castillo, E.R., Campón, F.F., Cigliano, M.M. & Confalonieri, V.A. (2023). Pleistocene climatic oscillations influenced the emergence of geographically widespread and restricted genetic lineages in an Andean grasshopper species group. Biological Journal of the Linnean Society 143: blad166. doi: 10.1093/biolinnean/blad166External link

Castillo, E.R.D., Scattolini, M.C., Palacios-Gimenez, O.M., Martí, D.A., Cabral-De-Mello, D.C. & Cigliano, M.M. (2023). Karyotype evolution in Ronderosia grasshoppers (Orthoptera: Acrididae). Zoological Journal of the Linnean Society 198: 351-367. doi: 10.1093/zoolinnean/zlac090External link 

Guzmán, N.V., Kemppainen, P., Monti, D., Castillo, E.R.D., Rodriguero, M.S., Sánchez-Restrepo, A.F., Cigliano, M.M. & Confalonieri, V.A. (2022). Stable inversion clines in a grasshopper species group despite complex geographical history. Molecular Ecology 31: 1196-1215. doi: 10.1111/mec.16305External link 

Santander, M.D., Cabral-de-Mello, D.C., Taffarel, A., Martí, E., Martí, D.A., Palacios-Gimenez, O.M. & Castillo, E.R.D. (2021). New insights into the six decades of Mesa's hypothesis of chromosomal evolution in Ommexechinae grasshoppers (Orthoptera: Acridoidea). Zoological Journal of the Linnean Society 193: 1141-1155. doi: 10.1093/zoolinnean/zlaa188External link 

Castillo, E.R.D., Martí, D.A., Maronna, M.M., Scattolini, M.C., Cabral-De-Mello, D.C. & Cigliano, M.M. (2019). Chromosome evolution and phylogeny in  (Orthoptera, Acrididae, Melanoplinae): clues of survivors to the challenge of sympatry? Systematic Entomology 44: 61-74. doi: 10.1111/syen.12317External link 

Palacios-Gimenez, O.M., Milani, D., Lemos, B., Castillo, E.R., Marti, D.A., Ramos, E., Martins, C. & Cabral-de-Mello, D.C. (2018). Uncovering the evolutionary history of neo-XY sex chromosomes in the grasshopper (Orthoptera, Melanoplinae) through satellite DNA analysis. BMC Evolutionary Biology 18: 2. doi: 10.1186/s12862-017-1113-xExternal link 

Castillo, E.R.D., Taffarel, A., Maronna, M.M., Cigliano, M.M., Palacios-Gimenez, O.M., Cabral-de-Mello, D.C. & Martí, D.A. (2017). Phylogeny and chromosomal diversification in the Dichroplus elongatus species group (Orthoptera, Melanoplinae). Plos One 12: e0172352. doi: 10.1371/journal.pone.0172352External link 

Castillo, E.R.D., Taffarel, A., Mariottini, Y., Fernández-Arhex, V., Martí, D.A. & Bidau, C.J. (2016). Neo-sex chromosomes in the maculipennis species group (Dichroplus: Acrididae, Melanoplinae): the cases of D. maculipennis and D. vittigerum. Zoological Science 33: 303-310. doi: 10.2108/zs150165External link 

Castillo, E.R.D. (2014). Evolutionary recycling of sex chromosomes in Neotropical Melanoplinae. Metaleptea 34: External link

Castillo, E.R.D., Taffarel, A. & Martí, D.A. (2014). The early evolutionary history of neo-sex chromosomes in Neotropical grasshoppers, (Orthoptera: Acrididae: Melanoplinae). European Journal of Entomology 111: 321-327. doi: 10.14411/eje.2014.047External link 

Palacios-Gimenez, O.M., Castillo, E.R., Marti, D.A. & Cabral-de-Mello, D.C. (2013). Tracking the evolution of sex chromosome systems in Melanoplinae grasshoppers through chromosomal mapping of repetitive DNA sequences. BMC Evolutionary Biology 13: 167. doi: 10.1186/1471-2148-13-167External link

Bidau, C.J., Martí, D.A. & Castillo, E.R. (2011). Inexorable spread: inexorable death? The fate of neo-XY chromosomes of grasshoppers. Journal of Genetics 90: 397-400.  doi: 10.1007/s12041-011-0108-4External link 

Castillo, E.R.D., Bidau, C.J. & Martí, D.A. (2010). Neo-sex chromosome diversity in Neotropical melanopline grasshoppers (Melanoplinae, Acrididae). Genetica 138: 775-786. doi: 10.1007/s10709-010-9458-8External link

Castillo, E.R.D., Martí, D.A., Bidau C.J. (2010) Sex and neo-sex chromosomes in Orthoptera: a review. Journal of Orthoptera Research 19: 213-231. https://doi.org/10.1665/034.019.0207External link